This invention relates to gas turbine engine air intake structure.
Gas turbine engines adapted for use in powering helicopters are usually provided with air intakes which are adapted to separate particulate material from the air which eventually enters the engine. One common form of air intake adapted to achieve this end comprises a duct defining the engine air inlet and a centre body positioned upstream of the duct. The centre body has a convex dome-shaped upstream facing face which is of a larger diameter than engine air inlet. Thus air which eventually enters the engine air inlet must first follow a sinuous path around the centre body. The momentum of any particulate material carried by the air ensures that instead of following the same sinuous path as the air, it tends to be thrown clear of the engine air inlet.
If the air drawn in by the engine additionally carries water droplets, some will be thrown clear of the engine air inlet in the same way as the particular material. However, the remainder impacts the centre body and breaks up into a large number of smaller droplets which, as a result of surface tension forces, tend to adhere to the centre body and eventually flow into the engine air inlet. This is a highly undesirable phenomenum if the droplets are of sea water since their presence in the engine invariably results in accelerated rates of engine component corrosion.